1. Field of the Invention
The present invention relates to a method for manufacturing a honeycomb structure.
2. Discussion of the Background
Exhaust gases discharged from conventional internal combustion engines such as a diesel engine contain particulate matter (hereinafter, also referred to as PM), and in recent years, the PM has raised problems because it is harmful to the environment and the human bodies.
For this reason, various honeycomb filters such as a honeycomb filter including a porous ceramic honeycomb structure have been proposed as filters for capturing PM in exhaust gases and purifying the exhaust gases.
Further, in recent years, such a filter for purifying exhaust gases is desired to be downsized. For this reason, a small-sized honeycomb structure, that is, a honeycomb structure whose longitudinal length (hereinafter, also referred to simply as a length) is short, is desired.
Japanese Patent Application Publication (KOKAI) No. 2001-162121 discloses an aggregated body (a honeycomb structure) of ceramic filters in which a plurality of filters including a porous ceramic sintered body are integrated by bonding peripheral faces of the filters to one another with a sealing material layer interposed therebetween.
A honeycomb structure of this kind can be manufactured by the following method.
First, a ceramic powder, a binder, a dispersion medium solution and the like are mixed together to prepare a wet mixture.
Next, the wet mixture is extrusion-molded, and the extrusion-molded body is cut into a predetermined length to manufacture a pillar-shaped honeycomb molded body.
Thereafter, a plug material paste is injected to a predetermined end portion of each cell of the honeycomb molded body to seal each cell at either one end. Next, the honeycomb molded body with the plug material paste filled therein is degreased and fired to manufacture a porous ceramic sintered body (honeycomb fired body) to function as a filter.
Next, side faces of the plurality of honeycomb fired bodies are bonded to one another with a sealing material interposed therebetween to manufacture an aggregated body of the honeycomb fired bodies, and the sealing material is dried and solidified to form a sealing material layer, and thereby a honeycomb block formed by bonding the side faces of the plurality of honeycomb fired bodies to one another with the sealing material layer interposed therebetween is manufactured. Thereafter, as required, the periphery of the honeycomb block is cut and a coat layer is formed on the periphery of the honeycomb block to manufacture a honeycomb structure.
The contents of Japanese Patent Application Publication (KOKAI) No. 2001-162121 are incorporated herein by reference in their entirety.